Process for the manufacture of artificial leather and parchment and products obtained thereby



March 26,1940. L M. c. HMPSAUR 2,195,239

PROCESS FOR TH'E MANUFAGTURE 0F ARTIFICIAL LEATHER -AND PARGHMENT AND PRODUCTS OBTAINED THEREBY Filed April 2, 1936 nig. l

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Lucien mde CMGY'IQS 3i-)oufl \NVENTOE,

vvparchmenting bath and by the rening of the pulp and the density of the paper; in this way it is possible to limit the parchmenting of thick Patented Mar. 26,1940

UNITED- STATES PATENT Vori-flier.

PROCESS FOR THE MANUFACTURE 0F FICIAL LEATHER AND PARCHMENT AND PRODUCTS OBTAINED THEREBY Lucien Marie Charles Champsaur, Paris, France Application April 2, .1936, Serial No. 72,307

In France April 12, 1935 4 Claims.

The object of the present invention is to provide improvements in processes for the manuthe feature that the treating bath is made to act upon a thickness of paper such that the transformation of the paper into parchment is effected over a fraction only of the thickness of this paper, this treatment being followed by cleaving, so that two sheets of paper are obtained, of which one face only is parchmented,. while the other face is soft anclv .velvety like the reverse side of animal leather or parchment and preserves the greater part of its absorbent properties, so that this paper can, for example, easily be cemented with any gum by means of its unparchmented face. 1 Y

A 'modification of the invention is characterised by the feature that a plurality of sheets of different thicknesses are caused to pass through the parchmenting bath, so as to parchment the thin sheets throughout and to parchment the thick sheet on its outer faces only. These sheet elements are welded together by pressure and finally the whole assembly is cleaved through the thickest sheet, thereby enabling a sheet to be obtained which has one unparchmented face and one face parchmented over a considerable thickness, this sheet thus havingan increased strength.'

The process forming the sub-ject of the invention is carried out by the means employed for the manufacture of vegetable parchment and with the same 'raw materials: paper without gum or dressing (Figure 1) passing through a parchinenting bath (sulphuric acid, phocyanate, etc.).

, The bath penetrates more or less deeply into thi paper and transforms the iibresIV of the impregnated part, but the penetration and the-impregnation resulting therefrom can be limited and regulated bycausingthe apparent or relative porosity ofthe paper to be varied and consequently its first absorption and its final parchmenting, .both by the viscosity of the papers to a single superflcialaction, while the zinc chloride, sul- Y fibres of the internal mass of the sheet which i .have been truly and effectively preserved from j any contact'with the bath to the degree of parchmenting, are not parchmented and remain in the natural state.

.It will be seen 'for example in Figure 2 that the faces l1|2 of the sheet of paper are alone parchmented; the internal part-I3 of this paper preserves the same texture that it had before passage through the` bath.

After this treatment by the parchmenting bath, the paper is washed and it is dried or if necessary it is. rendered flexible before drying.

The paper thus treated is then cleaved. For this purpose a tear is started in the paper along the central plane XX. As soon as this tearhas been started it is suilicient to pull the two sheets N2, while separating them from each other (Figure 3). This operation may moreover be effected easily by two rollers 2122 upon which the two sheets Ill2 are wound, the said rollers turn.- ing in the directions f1 and ,f2 (Figure 4). Two

sheetsare thus obtained, each having the ap-4 pearance shown in Figure 5; one of the faces I1 of each sheet is parchmented whilethe other face I3 comprises visible unparchmented fibres which are slightly raised by the cleaving operation and give a velvety appearance to this face.

The parchmentedface which imitates leather may be worked and varnished in order to form a decorative product for example.

The unparchmented face I3 may be coated with gum'in order to-apply the product upon any object. A

To sum up, the product obtained is not a parchment from both aspects, of homogeneous chemical composition, but is a heterogeneous product composed essentially of a paper whichhas preserved some of its libres in the natural state with their intrinsic qualities, the feltng of these libres, that is to say the ravelling of the fibres having been disorganised by the cleaving and one face only of the said paper having been rendered impervious by a surface parchmenting operation.

This product has the appearance of animal parchment but it has'A the advantage o ver this product, like vegetable .parchment that it is not attackedby fatty This parchment has all the properties` Yof so-called greaseproof parchment, and it may be employed for covering surfaces to be protected.

It can be smoothed, impressed, grained,

Y stamped or hammered, varnished or coated with same side of the thick sheet. I.

boards or being 'obtained by the superposition and cementing together of different cardboards. Numerous modifications may be made in the process described above, without on that account going outside the scope of the invention.

For "example, the action of the bath `may be continued a little further so that the bres are parchmented only upon the outer -faces of the initial sheet, while thebres in the interior of this sheet up to a more or less great depth, as

far as the line of cleavage XX', if necessary are provided with a superficial hydration giving to the fibres a finish similar to that obtained by mercerisation.

In this connection the essential difference between parchmenting and hydrating should be noted: parchmenting involves the formation of amyloid coating and welding together the fibres which are thus hardened and made rigid; 'on the contrary, hydrating which does not comprise the formation of amyloid only gives a superficial dressing to the fibres rendering them stronger but without hardening them or welding them to each other so that these fibres thus preserve all their flexibility.

Instead of starting with a single sheet of paper,

use may also be made of a plurality` of sheets. In-

this case one of the sheets has a considerable thickness, while the other sheets are much thinner. For example, three sheets I, 3`, 4 (Figure 6) are made to pass' simultaneously through the same parchmenting bath by arranging them relative to one another in such a manner that the two thinner sheets 3, tare situated on the 'I'hese sheets are guided by means of rollers 5, 6 in the tank 'I containing thebath; the same precautions are taken as before and in particular the sheets are left in the bath for only suiiicient time to parchment the thin sheets 3 and l throughout and the two outer faces I1I2 of the thick Sheet I.

Immediately upon the removal from the bath, the three sheets I, 3, 4 are united by pressure, by making them pass for example between two rollers 1, 8.

The pressure applied by these rollers welds the sheetsv I', 3, 4 together.

After passing between .these rollers, the single sheet obtained is washed and then dried. This sheet has the texture illustrated in Figure 7:.

(a) A thick sheet I, parchmented upon 'its (b) Two thin sheets 3, throughout and welded together and to the face I2 of the thick sheetI.

The assembly is then cleaved along the plane YY which coincides approximately with the cen'- tral plane of the thick sheetI I: the mode of operation is the 4same as before.

4.. parchmented After this operation, two sheets are obtained (Figures' and 9) of different natures:

(a) A sheet (Figure 8) formed by two thin sheets 3, 4 parchmented throughout and welded to the face I 2 of the thick sheet I.

(b) A sheet (Figure 9) analogous to the sheet shown in Figure5 and comprising a parchmented face I1 and a face I3 upon which 'can be seen the fibres of the paper which have been slightly raised by the cleaving operation.

The first of these sheets (Figure 8) thus has a considerable parchmented thickness and consequently a great strength, while it can easily be cemented by means of its unparchmented face I 3.

This product can thus advantageously replace leather.

Obviously the number of sheets of paper may be increased; the thick sheet'may moreover occupy any position without going outside the scope of the invention.

The invention includes not only the foregoing processes, but it also relates by way of new industrial products, to products conformingwith those obtained by the above processesand in particular:

' (a) A paper composed of a vegetable parchment having on one of its faces a layer of libres of the original paper serving for the manufacture of the parchment, this layer of libres being either in the natural4 state or simply provided with a finish, rendering this face soft and velvety.

(b) A paper formed of a plurality of sheets of paper parchment throughout and welded to `a sheet of paper, the free face of which is not parchmented.

Having now described my invention, what I claimas new and desire to secure by Letters Patent is:

1. A process for the manufacture of artificial leather and parchment, consisting in making the parchment bath act upon aA sheet of paper, in parchmenting this paper over a fraction only of its thickness and in cleaving this paper, thereby obtaining two sheets of paper of which one face only is parchmented, the other face preserving the greater part of its absorbent properties.

2. A process for the manufacture .of artificial leather and parchments, consisting in making the parchmenting bath act upon a sheet of paper, parchmenting the fibres of this paper over a fraction only of its thickness, superiicially hydrating the fibres of this paper over the remainder of its thickness, and cleaving this paper, thereby obtaining two sheets of paper of which one face only is parchmented, the other facepreserving/the greater part of its absorbent properties.

3. A vegetable parchment having a parchmented face and a soft and velvety face, formed by a layer of iibres of the original paper in an open vand disorganized state.

4. A` vegetable parchment having a parchmented face and a soft and velvety face formed by a layer of -supercially hydrated fibres in an open and disorganized state.

5. A product formed by vegetable parchment, having a parchmented face, and a soft and velvety unparchmented face having good absorbent properties and a sheet of cardboard cemented upon the said unparchmented face.

LUCIEN MARIE CHARLES CHAMPSAUR. 

